Aspects of the invention relate to a display device, a display method, and a projection type display device.
As information equipment has made remarkable developments, there has been an increasing demand for high resolution, less power consuming, and thin image display devices, and search and development are underway to provide such devices. Among all, a liquid crystal display device can electrically control the orientation of liquid crystal molecules and change the optical characteristics, and is expected to be a display device to satisfy the above demand. A projection type liquid crystal display device (liquid crystal projector) that expands and projects a display image emitted from an optical system using a liquid crystal valve on a screen with a projection lens is as an example of a related art liquid crystal display device.
The projection type liquid crystal display devices are divided into so-called three-plate type devices and single plate type devices. In the three-plate type device, light from the light source is for example separated into three R (red), G (green), and B (blue) color lights, and three liquid crystal light valves corresponding to these color lights are used to carry out optical modulation. The single-plate type device carries out optical modulation to the color lights using one liquid crystal light valve. The single plate type display device that uses only one liquid crystal light valve has a simple optical system accordingly, and therefore can be compact.
When color display is carried out using a white light source in the single-plate, projection type display device, there are two kinds of such display. One is a space divisional type display in which a liquid crystal light valve including a color filter is used and three dots for R, G, and B form one pixel. The other is a time divisional type display in which a white light is temporally separated into R, G, and B color lights using a color wheel or the like, and time divisional driving (color sequential display) is carried out using the liquid crystal light valve.
Techniques of irradiating R, G, and B color lights to a light valve using a light source (such as a light emitting diode (LED)) that emits these color lights instead of a white light source and a color filter have been disclosed. However, the quantity of light emitted from the LED is less than that of a light source, such as a lamp, and the displayed image could be dark. An image displayed by the color sequential display described above can be even darker, and techniques of brightening displayed images have been developed. See, for example, Japanese Patent Laid-Open No. 2002-251175.
In the disclosure of Japanese Patent Laid-Open No. 2002-251175, when an image is brightened based on the display content in a display device that carries out color sequential display, the color components of color lights R (red), G (green), and B (blue) are changed to C (cyan), Y (yellow), and M (magenta).
By the method disclosed by Japanese Patent Laid-Open No. 2002-251175, when the color components are changed (for example from (R, G, B) to (C, Y, M)), change in the brightness of the image can be disconnected. When the brightness change is disconnected in the image, the viewer may find the displayed image unnatural.